International Journal of Agricultural Technology

Fumigant toxicity of neem formulations against Sitophilus oryzae and Rhyzopertha dominica

2026-01-07T19:52:16+07:00

Fumigation toxicity of two neem formulations viz. Ware house neem I (mist and spray) and Ware house neem II (thermal fog) (Azadirachtin-1500 ppm in both) were studied against two major storage pests of maize, the rice weevil, Sitophilus oryzae and the lesser grain borer, Rhyzopertha dominica under laboratory conditions. The insects were confined in vials covered with cloth net (25 mesh) and were placed inside the fumigation chamber of 250 ml capacity. The lid was sealed by adhesive tape to create an air tight condition in the chamber. The adults were exposed to fumigants with and without grains. When the adults alone were exposed to WHN I, complete mortality of Sitophilus oryzae and Rhyzopertha dominica was observed at 15 µl and 30 µl / 250 ml and above doses, respectively at both the exposure periods (48 and 72 hours). Whereas in the case of WHN II, complete mortality of Sitophilus oryzae as observed at 50 µl in both exposure period and 93.33 per cent mortality of Rhyzopertha dominica observed at 250 µl with 72 hours exposure periods. Fumigation with grains required higher doses to cause the same level of mortality to that of fumigation with insects alone. Complete mortality of Sitophilus oryzae and Rhyzopertha dominica with WHN I was observed at 20 and 50 µl, respectively in 10 days of exposure period. In the case WHN II 100% mortality of Sitophilus oryzae was observed at 50 µl with 10 days exposure period, however only 50 per cent mortality of Rhyzopertha dominica was observed with 250 µl, which was five times higher than the former. Thus, Sitophilus oryzae was found more susceptible than Rhyzopertha dominica to fumigation of both formulations. The progeny emergence, percent damage and per cent weight loss were less in different doses of fumigants to both the pests when compared with untreated control. WHN I has more fumigation potential than WHN II to the test insects.

Frequency and abundance of zoosporic fungi in some lotic environments of Buenos Aires Province (Argentina)

2026-01-07T20:29:36+07:00

Zoosporic fungi are common inhabitants of aquatic environments; however, there are few quantitative studies made for Argentinean streams. In this contribution, the frequency of occurrence and abundance of zoosporic fungi were quantified in three lotic environments of the Río de La Plata system, using the baiting technique. Eight genera were recovered (Achlya, Aphanomyces, Dictyuchus, Olpidiopsis, Phytophthora, Pythium, Rhizophlyctis and Saprolegnia) and their patterns of frequency and abundance distribution show certain similarities in the streams analyzed.

Pathogenic interactions between Trichoderma species and Agaricus bisporus

2026-01-07T21:49:57+07:00

The interactions of Trichoderma harzianum, T. longibrachatum, T. virens and Trichoderma sp. with Agaricus bisporus mycelia were studied singly and in combination. Opposing cultures and layered cultures of the Trichoderma species with Agaricus bisporus mycelium produced a zone of inhibition. had The greatest colonization rates were in the order Trichoderma longibrachiatum, T. harzianum, T. virens and Trichoderma sp. Mycelial growth of Agaricus bisporus ceased upon contact with competitor hyphae all of Trichoderma species, after which parasitic growth continued over the A. bisporus mycelium in a radial manner. Microscopic observation of growth on 2% and 0.2% MEA showed different trends in interactions between the Trichoderma and mushroom mycelium. There was only superficial contact between the Trichoderma hyphae and A. bisporus in nutrient rich medium, but when the nutrient status of the medium was reduced, some coiling of A. bisporus hyphae by Trichoderma species was observed and hyphal lysis to occurred. However, the lysis of A. bisporus mycelia did not occur in all the species combinations. It is proposed that differences in metabolites produced by Trichoderma species have a close relationship with their colonization rate and subsequent mushroom losses. A severe interaction between T. harzianum and T. longibrachiatum with A. bisporus mycelium appears to be due to the production of lytic enzymes by the Trichoderma species. Volatile metabolites were either not produced by Trichoderma species or, if they were produced they had no inhibitory effects on A. bisporus mycelial growth.

Inhibitory effects of 8 toxic mushroom strains on growth and germination of Alternaria alternata

2026-01-08T05:17:44+07:00

The inhibitory effects of culture, filtered culture and ultra-sonified mycelial extracts of 8 toxic mushroom strains [Amanita virosa Lepiota clypeolaria Lactarius vellereus, Amanita pachycolea, Amanita sp., Ramaria ephemeroderma, Clitocybe dealbata, Lepiota cristata] on Alternaria alternata were studied. The culture extracts and filtered culture extracts inhibited the in vitro growth of Alternaria alternata. With the exception of Ramaria ephemeroderma and Lepiota cristata, ultra-sonified mycelial extracts also inhibited the growth of Alternaria alternata. With the exception of Amanita sp. and Ramaria ephemeroderma, the culture extracts also inhibited Alternaria alternata conidial germination. Lactarius vellereus had the strongest inhibitory effects on growth and germination of Alternaria alternata; the growth inhibitory rate and germination inhibitory rate of the culture extracts were 61.44 to 90%.

Thermophilous fungi from temperate soils of northern India

2026-01-09T06:13:32+07:00

Temperate soils of northern India were studied for thermophilic and thermotolerant fungi and 19 species belonging to 14 genera were isolated. Ten species were thermophilic and six were thermotolerant. Chaetomium senegalense (Ascomycetes) and Myceliophthora fergusii (anamorphic ascomycetes) are reported for the first time from India. The fungal “Colony Forming Units” (CFUs) in temperate soils were investigated by examining soil cores. Studies on importance value index (IVI) and numerical values for population numbers indicated that a higher number of CFUs and isolates occurred in Shimla soil. The temperature of the soil from which all fungi were isolated did not correspond with their optimum axenic growth temperature.

Effect of the application of alpha naphthyl sodium acetate (Aponon®) on colonization and production of spores of arbuscular mycorrhiza-forming fungi in lettuce (Lactuca sativa)

2026-01-10T12:29:50+07:00

The effect of a synthetic auxin, alpha naphthyl sodium acetate (Aponon®), was evaluated on the growth of lettuce plants (Lactuca sativa) and their associations with arbuscular mycorrhizal fungi. Percentage colonization, number of arbuscules, coils and vesicles and production of spores of arbuscular mycorrhizal fungi were evaluated. Lettuce plants were inoculated with three species of mycorrhizal fungi (Glomus clarum, G. intraradices and G. mosseae). Three doses of Aponon® (10.6 mg/l, 21.18 mg/l and 42.35 mg/l) were applied and both noninoculated controls and controls without the application of the synthetic hormone were used.
The plants were harvested after 90 days. Plants inoculated with G. clarum and with the highest dose of Aponon® resulted in the highest value for colonization. The higher the dose of Aponon®, the lower the colonization percentage in the plants inoculated with G. intraradices and G. mosseae. The percentage of arbuscules and vesicles showed a similar pattern to that of colonization in the plants inoculated with G. clarum and G. intraradices. The coils had low values in all treatments. Glomus mosseae and G. intraradices decreased their spore production as the dose of Aponon® increased, whereas G. clarum did not show differences in relation to the dose of Aponon®. The greatest plant biomass was observed in the plants inoculated with G. mosseae lacking or with minimal doses of Aponon®.

Cultivation of Thai and Japanese strains of Pleurotus sajor – caju on rice straw - based Volvariella volvacea mushroom spent and composted rice straw in Central Luzon Region, Philippines

2026-01-10T17:04:55+07:00

The mycelial and fruiting body performance of Thai and Japanese strains of Pleurotus sajorcaju were compared on two formulated substrates. Evaluation was based on incubation period of inoculated bags, number of days from complete mycelial colonization to primordial formation, number of days from opening the bags to first harvest, number of fruiting bodies per bag, average weight of individual fruiting bodies, total yield of fruiting bodies, diameter of individual pileus, length of stipe and biological efficiency. The Thai strain had a significantly shorter incubation period but longer number of days before primordia appeared. The Japanese strain yielded significantly higher yield and biological efficiency than the Thai strain. Pleurotus sajor-caju grown on Volvariella volvacea spent mushroom compost had a significantly faster incubation period, lesser number of days from complete mycelial colonization to primordial formation, higher yield and biological efficiency. Those grown in composted rice straw had a longer incubation period, took longer for complete mycelial colonization to primordial formation, and a lower yield and biological efficiency.

In vitro evaluation of anti-bacterial spectrum and phytochemical analysis of Acacia nilotica

2026-01-10T19:38:31+07:00

The antibacterial activity of aqueous extract, different solvent extracts and isolated constituents of leaves of Acacia nilotica (Family: Fabaceae) were evaluated by the cup diffusion method against three phytopathogenic Xanthomonas pathovars viz., Xanthomonas axonopodis pv. malvacearum, X. a. pv. phaseoli and X. campestris pv. vesicatoria associated with angular leaf spot of cotton, common blight of bean and bacterial spot of tomato respectively and 14 human pathogenic bacteria. Aqueous, methanol and ethanol extracts showed significant antibacterial activity against all the pathovars of Xanthomonas and 14 human pathogenic bacteria tested. Methanol extract was subsequently fractioned and monitored by bioassay leading to the isolation of active fraction by further phytochemical analysis. This active fraction recorded highly significant antibacterial activity in vitro (MIC 5, 6 and 7 µg/ml for Xanthomonas pathovars and 6-12 µg/ml for human pathogenic bacteria) compared with synthetic antibiotics like Bact-805 and K-cycline for phytopathogenic bacteria and Gentamicin and Streptomycin for human pathogenic bacteria. The results also revealed that further separation of active fraction resulted in the loss of antibacterial activity, indicating synergistic effect of the isolated active fraction.

Study on the growth patterns of transformed carrot hairy roots in an optimized system

2026-01-11T09:49:00+07:00

Growth patterns of transformed carrot hairy roots in an optimized system of root induction were studied. Inoculation of mature carrot root sections was carried out using a mixture of four isolates of Agrobacterium rhizogenes that had been grown in three culture media (LB, YMA and modified medium) with 36 hours incubation time before inoculation. Results showed that most assays resulted in hairy root formation, although this was not equal. The source of the carrot was one of the most important factors, with mature, freshly harvested carrots showing better hairy root production. These roots had the ability to quickly form numerous lateral roots as well as a negative geotropic growth habit. Lateral roots were initiated from the both sides of the carrot discs and occurred from 8-10 days to 3-4 weeks. Root growth on MW medium followed a distinct pattern over 20 days and root elongation rates did not have a regular exponential trend over time.

Diagnostics of phytopathogen infection in agricultural plants as a necessary condition for optimizing current fungicide application technologies

2026-01-11T11:43:00+07:00

The effectiveness of chemical protection of agricultural plants from diseases often depends not only on the fungicide applied, but also on correct terms of its application. The existing ways of determining probable necessity and terms of fungicide application are predominantly based on indirect prediction of plant infection. In the last years, techniques for direct diagnosis of plant phytopathogen infection in the latent phase have been intensively eveloped.
Methods for determining the necessity and terms of fungicide application include: indirect prediction of plant infection and direct diagnosis of plant infection. Technical schedule, phenological forecast, prognostic model of infection risk periods, visible manifestations of the earliest disease symptoms are list of the indirect prediction methods. Direct diagnosis of plant infection include the direct identification of pathogen in plant tissues (immunofluorescence staining, ELISA and PCR diagnostics) and detection of pathogen metabolic products ergosteroles and microtoxins.

Detection of Candidatus Liberibacter asiaticus causing Citrus Huanglongbing disease

2026-01-11T12:02:13+07:00

Detection of Candidatus Liberibacter spp. causing citrus Huanglongbing (HLB) disease was facilitated by taking samples from three different citrus orchards located in Chiang Mai, Chiang Rai, and Phrae provinces. A polymerase chain reaction (PCR) with specific primers OI1/OI2c and A2/J5 were used for detection and they produced specific band of 1160 bp and 703 bp, respectively. These were amplified from diseased leaves whereas no product from healthy citrus plants. To improve the method of detection for HLB disease, this study were a utilized five methods for pathogen DNA extraction from disease leaves and applied to a PCR; protocol three and four were most effective. When primers A2/J5 were used to identify the Liberibacter species, a 703 bp band was observed from all infected plants. The sequence of the bacterial ribosomal protein genes of samples from Chiang Mai (HLB-CM), Chiang Rai (HLBCR), and Phrae (HLB-P) were analysed. From these results, it is apparent that the causal agent of citrus HLB disease, in these provinces, is Candidatus Liberibacter asiaticus.

Extending the shelf life of lychee using different CO2:O2 ratios and an ethylene absorbent in polyethylene bags

2026-01-11T13:35:57+07:00

The extension of the shelf life and quality of lychee was examined by using CO2:O2 ratios plus an ethylene absorbent in polyethylene bags. The weight loss of lychee increased according to storage time. Lychee stored in 3% ethylene absorbent with CO2:O2 flow rates of 0:0 PSI lost the most weight with a mean of 1.44%. The total soluble solid content (17.10-17.9 brix) and titratable acidity (0.25-0.31%) of lychee slightly decreased in all treatments according to storage time. Lychee stored in 4% ethylene absorbent with CO2:O2 flow rates of 5:5 PSI resulted in the best acceptable quality and longest storage life of 18 days. Lychee stored in LDPE bags with CO O2 flow rates of 0:0 PSI lost the most weight with a mean of 1.70%. Total soluble solid content (15.73-17.2 brix) and titratable acidity (0.18-0.22%) in all lychee treatments decreased slightly according to storage time. Lychee stored in PE bags with CO2:O2 flow rates of 5:5 PSI had the best performance and longest storage life of 18 days with acceptable quality.